It has been proposed to form tape structures from polypropylene film that is coated with a layer of propylene copolymer including ethylene units such that the coating has a lower softening point than the core. Such tape structures are disclosed, for example, in U.S. Pat. No. 5,578,370 the teachings of which are herby incorporated by reference in their entirety. U.S. Patent Application 2004/0242103A1 (incorporated by reference) has also proposed to form monoaxially drawn tape structures characterized by substantial draw ratios and incorporating a central layer of a polyolefin with one or two covering layers of a polyolefin from the same class as the central layer. The DSC melting point of the outer layers is lower than that of the central layer to facilitate heat bonding. Such drawn tape elements may be interwoven so as to form a mat structure which is then subjected to heat thereby fusing the tape elements in place. Multiple layers of such interwoven mat structures may be combined to form moldable structures of substantial thickness that may be shaped to three-dimensional configurations.
While the moldable mat structures of the prior art are highly useful for a number of end uses, it has been found that the surface character of the olefin tape elements tends to reduce adhesion between the formed mat and applied substrate layers incorporating materials such as adhesives, resins, foams, plastics, rubbers and the like. In particular, the covering layers of low melting point polyolefin may facilitate delamination. Accordingly, the need exists to provide a system that facilitates lamination while nonetheless maintaining the desirable moldable properties of the mat structures.